@InProceedings{CoutoOishSardFerr:2017:ElPeTh,
author = "Couto, Andrea Boldarini and Oishi, Silvia Sizuka and Sardinha,
Andre Ferreira and Ferreiraa, Neiden{\^e}i Gomes",
affiliation = "{} and {Instituto Nacional de Pesquisas Espaciais (INPE)} and
{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)}",
title = "Electrocatalytic performance of three dimensional electrode
Cu/reduced oxide graphene/ carbon fiber for nitrate reduction",
year = "2017",
organization = "ECS Meeting, 232.",
abstract = "Nitrate ions are well-known water toxic inorganic pollutants and
their high concentrations can cause a serious problem for both
aquatic systems and human health. In this sense, it is of great
importance to monitor nitrate ions in various kind of source [1].
Among several analytical technologies that been used for its
detection, electrochemical technique offers a simple, rapid,
selective, sensitive, inexpensive, safety method for this purpose,
not to mention its considered green technology [2]. To improve the
nitrate process performance and selectivity, novel electrode
materials have been widely investigated. This work aims to develop
a sensitive and reliable three dimensional electrode consisting of
Cu particles/reduced oxide graphene (rGO)/carbon fiber (CF) for
monitoring nitrate concentration. CF produced at heat treatment
temperature of 1000 ºC was used in this study. The rGO
electrodeposition on CF (1 cm2) was performed at a fixed potential
of -1.25 V vs. Ag/AgCl/KCl(sat) for 15 min in a 20 mL of the
graphene oxide (3mg mL-1) + 0.1 mol L-1 LiClO4 aqueous solution.
The Cu electrodeposition on rGO/CF was carried out at a fixed
potential of -0.7 V for 3, 6, 10, 20 min in a 10 mmol L-1 CuSO4 +
100 mmol L-1 H2SO4 aqueous solution. Cu/rGO/CF composites
morphologies and structures were analyzed by field emission gun
scanning electron microscopy (FEG-SEM), X-ray diffraction, and
Raman spectroscopy. Nitrate electro-reduction was evaluated using
cyclic voltammetry at 50 mV s-1 in 0.1 mol L-1 K2SO4 solution (pH
= 3.0) with and without the presence of 10-2 mol L-1 KNO3. For
rGO/CF binary composite, FEG-SEM images showed the characteristic
aggregates with irregular and flakes-like shape with high particle
density on CF substrate. The Cu deposits depicted small grain
morphologies distributed throughout the rGO/CF surface. As
expected, Cu deposit rate increased with increasing the deposition
time. From X-ray diffraction analyses of the Cu particles, a
mixture of phases containing cuprous oxide and metallic copper was
identified. Under optimal experimental conditions, the Cu/rGO/CF
electrode showed good catalytic activity for nitrate
electro-reduction. This behavior can be associated to the presence
of rGO and CF with high specific surface area in addition to Cu
particle with high electron transfer capability. These results
showed that Cu/rGO/CF composite has a great potential as new
promising electrode for nitrate electroreduction application.",
conference-location = "National Harbor, MD",
conference-year = "01-05 Oct.",
language = "en",
urlaccessdate = "27 abr. 2024"
}